OK, looks like there are at least a couple of dependencies that were not detailed in the build instructions. So I've been tracking them down.

I think once I find them all it should actually build. Complicating the issue is that for some reason the Mint repositories seem to be pretty slow so it is taking a long time to install and then I need to rebuild to see what is next on the missing list.

EDIT: I found another page with some more complete list of dependencies so I was finally able to get the build to complete. Now working though the interactive tutorial. At the moment hung up on how to move though the icon picker to find the cog icon. It moved though a page at a time if I selected an icon on the current page but I haven't figured out how to actually navigate it just yet. So off to dig that information up.